<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			*{
				margin: 0;
				padding: 0;
			}
		
			html{
				height: 100%;
			}
			body{
				width: 60%;
				height: 60%;
				border: 1px solid;
				margin: 100px auto 0;
			}
		
			#test{
				width: 200px;
				height: 200px;
				border-radius:50% ;
				background: pink;
				text-align: center;
				font: 30px/100px "微软雅黑";
				
				/*display: block;*/
				
				position: absolute;
				left: 0;
				right: 0;
				bottom: 0;
				top: 0;
				margin: auto;
				
				transition-property: background,width,height;
				transition-duration: 1s,0s,1s;
			}
			
			body:hover #test{
				width: 100px;
				height: 100px;
				background:black;
				
				/*display: none;*/
			}
			
		</style>
	</head>
	<body>
		<div id="test">
		</div>
	</body>
</html>
